Using discrete choices to elicit preferences is a major tool to help guide public policy. Although Discrete Choice Experiment (DCE) remains by far the most popular mechanism used to elicit preferences, its reliability still is questionable. Using an induced value experimental design, we show that standard benchmarks achieve no more than 56% (hypothetical answers with no monetary incentives) to 60% (real monetary incentives) of payoff maximizing choices. Herein we demonstrate that having respondents sign a the truth-telling oath reduces non-payoff maximizing choices by nearly 50% relative to these benchmarks. The explicit and voluntary commitment to honesty improved decisions. Further, we show that it is the explicit commitment to honesty induced by the truth-telling oath improves choices, not just any oath mechanism, i.e., an oath to task or to duty did not improve choices.